Sludge is firstly flocculated in-line with a polyelectrolyte and enters the machine.

The machine consists of a main case, internal screw rotating at <1.5rpm), spray bar and cylindrical wedgewire/mesh drum. As the sludge enters the unit the sludge is conveyed by the screw through the drum length whilst the filtrate is drained through the mesh. The drum consists of variable apertures and profiles, and together with a reducing screw pitch and increased shaft diameter, pressure is gradually applied to the sludge mass.

The ultimate high pressure zone is at the outlet section where an adjustable pneumatic cone is configured to achieve maximum sludge dryness. The cake is discharged through the cone into a bin or conveyor systems and the filtrate collects within the main case and is discharged via gravity to the filtrate outlet flange.